The present invention relates generally to a connector and, more particularly, to a self-locking connector in which uncoupling movement of the coupling nut of the connector is restrained.
While the present invention will be described specifically in connection with electrical connectors, it will be appreciated that the invention in adaptable for use with other forms of connectors, such as fiber optic connectors. Typically, the plug and receptacle connector members of an electrical connector are assembled together either by a bayonet type connection, or a threaded coupling nut. The threaded coupling nut has the most mechanical reliable configuration but, unlike the bayonet coupling arrangement, the threaded coupling nut does not inherently include means for resisting uncoupling when the connector is subjected to vibrations or means for audibly indicating when the mating halves of the connector are securely and firmly joined.
When connectors are utilized in aircraft and space vehicles, for example, they are often subjected to high vibrations. Consequently, connectors require some means for assuring that the mating halves of the connector will not uncouple, thus assuring electrical integrity during use of the connector. Furthermore, it is desirable to provide in a connector means which produces an audible indication of complete mating of the connector halves since the connectors may be located or mounted in virtually inaccessible locations where visual inspection of the connector is not possible.
Threaded electrical connectors have been developed which have a self-locking mechanism which produces an audible, and sometimes tactile indication of mating of the connector halves. For example, a U.S. Pat. No. 3,552,777 to Heinrich et al. discloses a self-locking electricial connector utilizing balls which cooperate with detents in a clicker plate. U.S. Pat. No. 3,808,580 to Johnson discloses a similar self-connector in which rounded projections are formed on a ring rather than a plurality of balls. U.S. Pat. No. 4,165,910 to Anderson discloses a self-locking connector in which a locking spring embodies radially extending fingers which engage detents formed on the inner surface of a coupling nut. U.S. Pat. No. 3,669,472 to Nadsady discloses a pipe coupling employing an annular ring on one coupling member having axially extending spring fingers cut out and bent forwardly therefrom which engage recesses formed in the mating coupler member. A similar locking spring is disclosed in U.S. Pat. No. 3,611,260 to Colardeau et al. All the aforementioned self-locking coupling arrangements have the disadvantage that the clicking or detenting occurs throughout the mating cycle so that there is not a clear indication of the fully mated condition of the connector assembly.
U.S. Pat. No. 3,594,700 to Nava et al. discloses a self-locking electrical connector employing a generally cylindrical locking ring which is slotted to provide narrow strips which are resilient radially so that projections formed on the strips may resiliently engage teeth formed on the inside of a coupling nut. The ring embodies an inwardly extending annular flange which is trapped between the shells of the mating connector members close to the end of the mating cycle to prevent rotation of the locking ring, so that continued rotation of the coupling nut will produce a clicking action when the detents thereon ride over the projections on the locking spring. U.S. Pat. No. 4,290,662 to Storcel discloses another form of a self-locking connector in which detenting occurs toward the end of the mating cycle by a cam ring being forced axially against detent protrusions formed on a wavespring washer behind the cam ring.
It is the object of the present invention to provide a relatively simple, low-cost and easy to assemble self-locking mechanism for a connector which is activated near or at the end of the mating engagement of the connector members and provides a clear audible indication of the fully mated condition of the connector.